A network of batteries can be used to provide power source redundancy for critical consumer and commercial applications. The battery network includes several batteries connected together in series, parallel, or other combinations. The applications can be active or passive. In one example, an active battery network powers a consumer's electric automobile. In another example, a passive battery network provides redundancy and failover protection for a commercial sever system using electricity wired from a power grid as a primary power source.
Battery performance can degenerate or become unreliable in response to the presence of manufacturing defects or the development of conditions such as grid corrosion, sulfation, or loss of water. Accordingly, maintenance of battery networks is important to ensure reliable performance. In particular, battery testing provides an instantaneous snapshot of performance and identifies dead batteries. Typically, the testing of a battery for performance characteristics such as cold cranking amps, state of charge, and the like require that it be removed from use. Alternatively, a battery network can be deactivated and tested as a whole.
Problematically, state of the art techniques do not provide advance warning of which batteries of a battery network are failing, why they are failing, or the severity of the failure (i.e., how soon batteries are likely to fail). As a result, it is difficult to ascertain a state of health for a battery network as a whole. It is also difficult to assess the threat of a given state of health to a particular application. Furthermore, the difficulty and time commitment for battery isolation or removal can lead to less frequent testing. Moreover, testing of a battery network as a whole ignores the condition of individual batteries. In critical applications, it is common for the entire battery network to be replaced even if only a few of the individual batteries are failing.
Therefore, what is needed is a method for testing battery networks that can be applied while the batteries are in operation, that takes into account both individual and overall battery health, and that can make adjustments for the needs of a particular application.